One of the cardinal rules governing the design of racing cars is that every conceivable means to lighten the chassis, engine, transmission, etc., is employed as long as it does not impair the performance of the car. The reason for this, is that given the same power plant, the lighter of two otherwise identical cars will obtain a higher speed for a given horsepower.
Two of the biggest problems faced today in automobile racing are the desire for an optimum power to weight ratio, and the need for reliability in the parts being used. An example of one proposed solution to the problem would be the single speed transmission now being used by the United States Auto Club Sprint Car Division. These transmissions while lighter than a full four or five speed racing transmission, are not only expensive, but must be specially constructed for the racing car being used. They also offer only one speed, thus allowing the driver only the choice of in gear or out of gear operation. While this may be fine during full racing speeds; it also causes such problems as spark plug fouling during slow traffic or caution periods during a race.
Another example would be the 4, 5 or 6 speed racing transmission commonly used in all other types of racing cars today. While these overcome the previous disadvantages of the one speed transmission; they are also disadvantageous because of the increase in power to weight ratios, and the increased likelihood of mechanical failure due to the additional moving parts required for the unused gears.
The intended purpose of this invention is to provide a two speed racing transmission which is lightweight to provide an improved power to weight ratio; which is easily adapted to the majority of oval track racing cars; and further allows the racing driver a choice of full speed gearing, or gearing for lower speeds, so that the RPM'S of the engine can be kept at an increased level to maintain optimum performance. Also, with fewer moving parts, and a simplified shifting linkage resulting from the proposed construction, reliability will be greatly improved.
Since the 1 speed transmission is very expensive to manufacture, and the multi-speed transmission add weight and torque to the transmission through the lower speed ratio gear clusters and linkages which are only employed a fraction of the time, a compromise has been sought.
While it might seem a simple concept to arrive at a solution to the aforementioned problem by developing a two-speed transmission which only employs the higher speeds, it is neither simple nor obvious to arrive at the method and apparatus which forms the basis of this invention.
On its face the most logical solution to the problem, would be to design and construct a totally new two speed transmission. However, this solution would prove to be even more expensive than the single speed transmissions mentioned supra.
On the other hand, the solution provided by this invention is unique; in that it takes an existing multi-speed transmission, and converts it into a lightweight two speed transmission, by virtue of a simple modification process, which employs very few, and inexpensive, additional parts. The resultant transmission is extremely reliable, lightweight, easier to shift, and has a vastly improved power to weight ratio and performance characteristic over any existing transmission.